Evaporator



Jan. 1 1946. J. J. McANDRl-:ws

EVAPORA'IOR Filed Oct. 20, 1945 I N V EN TOR. Jhn JCncZreu/s Patented Jan. 1, 1946 vUNITED STATES PATENT OFFICE EVAPORATOR John J. McAndrews, Hempstead, N. Y.

Application October 20, 1943, Serial No. 506,939

z Claims. (C1. 15s-23) This invention relates to evaporators and more particularly to evaporators adapted to be used fOr procuring Water for boilers and other uses on ships and other places.

While quite obviously my evaporator may be used in any number of Ways it is particularly adaptable for use in evaporating salt Water. With the evaporators now in use considerable diculty is encountered in cleaning the tubes and in keeping the evaporator in eillcient condition. As salt water is evaporated the salt forms a coating on the tubes and other parts of the evaporatorhwhich tends to insulate them and generally to cut down the efliciency. It is then necessary to take the evaporator out of service and to manually clean the tubes and other parts.

An advantage of the present invention rests in the simplied method of cleansing the tubes and in removing foreign deposits therefrom.

In the accompanying drawing- Figure 1 is a side elevation partly in section oi an evaporator embodying my invention;

Fig. 2 is an end view -thereof Fig. 3 is a cross sectional View of the construction of the tubes.

My invention I comprises a boiler of any desired shape having a bank of tubes Il mounted therein. The tube bank is constructed with a double head I2 provided with separate chambers I4 and I5. The tubes I6 are closed at one end Il and have inner tube members I8 through the open ends I9. Steam is introduced into the chamber I4 through the inlet 25 then passes through the tubes I8 out the end 26 thereof. The steam then passes back through the tubes I6 around the tubes I8 and into the chamber I5 Where it passes through the outlet 2l back to the boilers.

The opening 25 is provided with a valve 28 and additional valves may be provided as necessary.

In operation, salt water is introduced into the evaporator III up to the level of the tube bank II. Steam is introduced into the tubes through the inlet 25. A vacuum is maintained within the evaporator and the water will therefore evaporate below the normal boiling point. As the water evaporates it is taken off through the pipes 30.

When it is desired to clean my evaporator to remove the salt crust from the tube bank I I steam is introduced into the tubes in the usual Way and cold water introduced into the pipe 3l. The pipe 3l has a series of openings 32 and is placed over the tube bank. As the cold Water is introduced through the pipe 3| it is sprayed through the openings 32 over the entire tube bank, thus suddenly cooling the tubes and causing them to contract. This pulls the tubes away from the salt crust and causes it to break and fall off into the bottom of the evaporator. It may then be cleaned out through the port 35 or the opening 36 and it is not necessary to manually remove the salt crust from the tubes.

My evaporators may be used with high or low pressure andtwo or more evaporators may be connected in a series.

I claim: 1. An evaporator comprising a vacuum chamber, a bank of horizontally disposed tubes within said chamber, said tubes being closed at one end thereof, a plurality of pipes, one in each of said tubes, means for introducing steam into said tubes through said pipes, means for removing deposits on said tubes, said latter means including a cold Water spray positioned abovesaid tubes for suddenly contracting said tubes beyond the contracting limit of said deposits.

2. An evaporator including a vacuum chamber, a plurality oi tubes horizontally mounted in said chamber, said tubes being closed at one end and having their open end connected to a common head, a second head, a plurality of pipes mounted in said second head and extending through said first-mentioned head into said tubes, one pipe in each of said tubes, means for introducing steam through said pipes into said tubes and means for suddenly contracting said tubes beyond the contracting limit of salt crust, said means comprising a cold water spray positioned over said tubes.

JOHN J. MCANDREWS. 

